ABSTRACT
Recognition of the wide diversity of organisms that maintain complex haploid-diploid life cycles has generated interest in understanding the evolution and persistence of such life cycles. We empirically tested the model where complex haploid-diploid life cycles may be maintained by subtle/cryptic differences in the vital rates of isomorphic haploid-diploids, by examining the ecophysiology of haploid tetraspores and diploid carpospores of the isomorphic red alga Chondrus verrucosus. While tetraspores and carpospores of this species did not differ in size or autofluorescence, concentrations of phycobiliproteins of carpospores were greater than that of tetraspores. However, tetraspores were more photosynthetically competent than carpospores over a broader range of photosynthetic photon flux densities (PPFDs) and at PPFDs found at both the depth that C. verrucosus is found at high tide and in surface waters in which planktonic propagules might disperse. These results suggest potential differences in dispersal potential and reproductive success of haploid and diploid spores. Moreover, these cryptic differences in ecological niche partitioning of haploid and diploid spores contribute to our understanding of some of the differences between these ploidy stages that may ultimately lead to the maintenance of the complex haploid-diploid life cycle in this isomorphic red alga.
Subject(s)
Diploidy , Rhodophyta , Animals , Haploidy , Life Cycle Stages , SporesABSTRACT
BACKGROUND: Factitious hypoglycemia is a condition of self-induced hypoglycemia due to surreptitious administration of insulin or oral hypoglycemic agents. In adults, it is an uncommon, but well known clinical entity observed in individuals with and without diabetes. OBJECTIVES: To report a case of factitious hypoglycemia highlighting diagnostic pitfalls, to identify common characteristics of children and adolescents with factitious hypoglycemia, and to examine whether the information on long-term outcome exists. METHODS: We present a case of an adolescent with type 1 diabetes who had self-induced hypoglycemia of several years' duration; and we conducted a systematic literature review on factitious hypoglycemia in pediatric patients with diabetes. RESULTS: We identified a total of 83 articles of which 14 met the inclusion criteria (describing 39 cases). All but 1 individual had type 1 diabetes and the majority was female (63%). Average age was 13.5 ± 2.0 years with the youngest patient presenting at the age 9.5 years. Blood glucose control was poor (hemoglobin A1c: 12.1 ± 4.0%). In 35%, psychiatric disorders were mentioned as contributing factors. Only 3 reports provided follow-up beyond 6 months. CONCLUSIONS: Factitious hypoglycemia typically occurs in adolescents with type 1 diabetes who use insulin to induce hypoglycemia. Awareness of this differential diagnosis and knowledge of potentially misleading laboratory results may facilitate earlier recognition and intervention. Little information exists on effective treatments and long-term outcome.
Subject(s)
Diabetes Mellitus, Type 1/diagnosis , Factitious Disorders/chemically induced , Factitious Disorders/diagnosis , Hypoglycemia/chemically induced , Insulin/adverse effects , Adolescent , Blood Glucose/drug effects , Blood Glucose/metabolism , Diabetes Mellitus, Type 1/blood , Diagnosis, Differential , Female , Humans , Hypoglycemia/diagnosis , Insulin/administration & dosageABSTRACT
The surgical techniques and outcomes of acetabular reconstruction for periprosthetic pelvic discontinuity cases are reported. The mean time to surgery for 9 patients with acute pelvic discontinuity was 16.3 days, with 8 patients (88%) having posterior column plating and a porous metal acetabular cup. No cases required revision surgery, with a mean follow-up of 34 months (range, 24-67 months). Of the 62 chronic pelvic discontinuity cases, 20 had an ilioischial cage, with a revision rate of 29%. There were 42 cup-cage reconstructions with an 8-year survivorship of 86.3%, with a mean follow-up of 35 months (range, 24-93 months). Stable reconstruction of chronic pelvic discontinuity was achievable by distraction using a cup-cage acetabular reconstruction; however, satisfactory stability of acute pelvic discontinuity was achieved with compression of the posterior column using screw augmentation of the acetabular shell supplemented by posterior column plating.
Subject(s)
Acetabulum/injuries , Acetabulum/surgery , Bone Diseases/surgery , Fractures, Bone/surgery , Hip Prosthesis , Adult , Aged , Aged, 80 and over , Female , Humans , Middle AgedABSTRACT
Mind-body interventions have gained increasing popularity for use with anxiety symptoms; however, it is unclear what role they play in the treatment of anxiety disorders, such as generalized anxiety disorder, panic disorder, and social anxiety disorder. Although psychopharmacology and psychotherapy treatment interventions are available, mind-body interventions may be low-stigma options that can serve as effective alternatives. The goal of this review is to provide clinicians with an overview of high-quality studies for the most well researched mind-body interventions. This review involved a search of the primary literature, including meta-analyses, systematic reviews, and randomized controlled trials (RCTs), that evaluated mind-body interventions for the treatment of anxiety disorders. When published evidence was limited, lower-quality studies were reviewed. Overall, data were limited on the efficacy of most mind-body modalities for anxiety disorders. The highest-quality data existed for yoga, mindfulness-based interventions, and applied relaxation for anxiety disorders. However, findings were sometimes inconsistent across studies, and some studies were limited by small sample sizes, poorly defined randomization and blinding procedures, and inadequate control groups. Although not enough data exist to recommend mind-body interventions as primary treatment options, they may be considered as part of a larger treatment plan given their relatively low levels of risk. Future steps for researchers include conducting additional RCTs with adequate control groups, comparing mind-body treatments with existing treatments, and examining long-term effects of mind-body interventions.
ABSTRACT
Metal-on-metal (MoM) hip bearings are being inserted into ever-younger patients. The effects on the immune system of chronic exposure are unknown. We investigated the immune response of patients with MoM hip bearings. In patients with MoM implants, the expression of antigen-presenting cell (APC) surface molecules (CD86 and HLA-DR) was seen to be significantly higher (P < .05) than control group. High levels of APC surface molecules suggest an activated state and attempts to propagate an immune response. However, in the same group, the expression of T-cell markers (CD3 and CD28) was low, indicating a small T-cell population. This suggests, despite the activation of APCs, that T cells down-regulate immune responses in MoM articulations. Conversely, in metal-on-polyethylene articulations, expression of T-cell molecules was elevated and expression of APC molecules lowered.
Subject(s)
Arthroplasty, Replacement, Hip , Hip Prosthesis , Immune System/physiology , Metals , Adolescent , Adult , Aged , Antigen-Presenting Cells/immunology , B7-2 Antigen/blood , CD28 Antigens/blood , CD3 Complex/blood , Follow-Up Studies , HLA-DR Antigens/blood , Hip Joint/immunology , Hip Joint/surgery , Humans , Longitudinal Studies , Middle Aged , T-Lymphocytes/immunology , Young AdultABSTRACT
Debate regarding the co-existence of Staphylococcus aureus and Pseudomonas aeruginosa in wounds remains contentious, with the dominant hypothesis describing a situation akin to niche partitioning, whereby both microorganisms are present but occupy distinct regions of the wound without interacting. In contrast, we hypothesised that these microorganisms do interact during early co-colonisation in a manner beneficial to both bacteria. We assessed competitive interaction between S. aureus and P. aeruginosa in biofilm cultured for 24-72 h and bacterial aggregates analogous to those observed in early (<24 h) biofilm formation, and interaction with human keratinocytes. We observed that S. aureus predominated in biofilm and non-attached bacterial aggregates, acting as a pioneer for the attachment of P. aeruginosa. We report for the first time that S. aureus mediates a significant (P < 0.05) increase in the attachment of P. aeruginosa to human keratinocytes, and that P. aeruginosa promotes an invasive phenotype in S. aureus. We show that co-infected keratinocytes exhibit an intermediate inflammatory response concurrent with impaired wound closure that is in keeping with a sustained proinflammatory response which allows for persistent microbial colonisation. These studies demonstrate that, contrary to the dominant hypothesis, interactions between S. aureus and P. aeruginosa may be an important factor for both colonisation and pathogenicity in the chronic infected wound.
Subject(s)
Biofilms/growth & development , Microbial Interactions , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/growth & development , Bacterial Adhesion , Cell Line , Coinfection/microbiology , Coinfection/pathology , Cytokines/metabolism , Enzyme-Linked Immunosorbent Assay , Humans , Keratinocytes/immunology , Keratinocytes/microbiology , Models, Biological , Pseudomonas Infections/microbiology , Pseudomonas Infections/pathology , Pseudomonas aeruginosa/physiology , Staphylococcal Infections/microbiology , Staphylococcal Infections/pathology , Staphylococcus aureus/physiologyABSTRACT
OBJECTIVES: The purpose of this study was to study the initial fixation and migration pattern of a monoblock acetabular component used for a metal on metal hip resurfacing using Einzel Bild Roentgen Analyse (EBRA). METHODS: 99 patients with a mean age of 49.6 years (range 28.5-66.3 years) of whom 14 were bilateral underwent a hip resurfacing (Conserve Plus®, MicroPort, Memphis, TN) for a total of 113 resurfacings. Acetabular component orientation was noted with 35 of the 113 components (31.0%) having a lucency >2 mm on the immediate postoperative radiograph. RESULTS: The mean follow-up for our cohort of 113 hips is 50 months (2-79 months). When examining the 2-year migration mark, 37 of the 113 hips exceeded the threshold of 0.5 mm/year with a median total migration of 1.40 mm (range 1.02-4.24). 6 resurfacings underwent revision surgery for aseptic loosening of the acetabular component at a mean time of 43.6 months. Presence of initial lucency (OR 2.29, p = 0.05) was the only significant predictor of migration over threshold at 2-years. Those that had migrated over the threshold (1.0 mm) at 2 years were at significantly greater risk of continued migration at 4 years. CONCLUSIONS: The migration pattern of this component raises concerns about long term performance, with postoperative lucencies representing a significant factor for future migration.
Subject(s)
Arthroplasty, Replacement, Hip/adverse effects , Foreign-Body Migration/surgery , Metal-on-Metal Joint Prostheses/adverse effects , Prosthesis Failure , Adult , Age Factors , Aged , Arthroplasty, Replacement, Hip/methods , Chromium Alloys/adverse effects , Cohort Studies , Female , Follow-Up Studies , Foreign-Body Migration/diagnostic imaging , Hip Prosthesis , Humans , Logistic Models , Male , Middle Aged , Reoperation/methods , Retrospective Studies , Risk Assessment , Sex Factors , Time Factors , Tomography, X-Ray Computed/methods , Treatment OutcomeABSTRACT
An understanding of the factors influencing the thermal stability of ultrathin carbon overcoats (COCs) is crucial for their application in heat-assisted magnetic recording (HAMR) at densities ≥ 1 Tb/in(2). Two types of non-hydrogenated ultrathin (â¼1.5 nm) COCs were investigated after being subjected to laser-induced localized heating (at temperatures > 700 K) as envisaged in HAMR. Filtered cathodic vacuum arc (FCVA)-processed carbon with tuned C(+) ion energies of 350 eV followed by 90 eV provides significantly higher sp(3) C-C hybridization than magnetron sputter deposition even at very low thicknesses of â¼1.5 nm. As a result, the FCVA-deposited ultrathin carbon overcoats displayed excellent thermal stability along with improved wear and corrosion resistance. On the other hand, the sputtered carbon exhibited carbon loss and topographical and structural changes after laser irradiation owing to lower sp(3) hybridization. Therefore, this study highlights the pivotal role of carbon microstructure, primarily sp(3) hybridization, in non-hydrogenated carbon overcoats to maintain excellent thermal stability during the recurring high-temperature cycles in a HAMR process.
ABSTRACT
The fallopian tube is now generally considered the dominant site of origin for high-grade serous ovarian carcinoma. However, the molecular pathogenesis of fallopian tube-derived serous carcinomas is poorly understood and there are few experimental studies examining the transformation of human fallopian tube cells. Prompted by recent genomic analyses that identified cyclin E1 (CCNE1) gene amplification as a candidate oncogenic driver in high-grade serous ovarian carcinoma, we evaluated the functional role of cyclin E1 in serous carcinogenesis. Cyclin E1 was expressed in early- and late-stage human tumor samples. In primary human fallopian tube secretory epithelial cells, cyclin E1 expression imparted malignant characteristics to untransformed cells if p53 was compromised, promoting an accumulation of DNA damage and altered transcription of DNA damage response genes related to DNA replication stress. Together, our findings corroborate the hypothesis that cyclin E1 dysregulation acts to drive malignant transformation in fallopian tube secretory cells that are the site of origin of high-grade serous ovarian carcinomas.
Subject(s)
Cell Transformation, Neoplastic/genetics , Cyclin E/genetics , Cystadenocarcinoma, Serous/genetics , Fallopian Tube Neoplasms/genetics , Fallopian Tubes/pathology , Oncogene Proteins/genetics , Ovarian Neoplasms/genetics , Cell Proliferation , Cyclin E/metabolism , Cystadenocarcinoma, Serous/metabolism , Cystadenocarcinoma, Serous/secondary , Epithelial Cells/metabolism , Epithelial Cells/pathology , Fallopian Tube Neoplasms/pathology , Fallopian Tubes/metabolism , Female , Gene Amplification/physiology , Gene Expression Regulation, Neoplastic , Humans , Oncogene Proteins/metabolism , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/secondary , Tissue Array Analysis , Tumor Cells, CulturedABSTRACT
Metal-on-metal bearings have become more popular for hip arthroplasty in younger patients in the last 15 years. We present a review of the neurological consequences relating to such bearing surfaces illustrated by an appropriate case report. The mechanisms of increased metal ion production and pseudotumour formation are discussed. If unexplained neurology, hip/groin pain or a localised mass around the hip are present with a metal bearing hip then urgent referral to a specialist orthopaedic surgeon is warranted for consideration of exchange arthroplasty.
Subject(s)
Granuloma, Plasma Cell/chemically induced , Metals/adverse effects , Peripheral Nervous System Diseases/chemically induced , Prosthesis Design , Prosthesis Failure/adverse effects , Aged , Female , Femoral Nerve/drug effects , Femoral Nerve/injuries , Femoral Nerve/pathology , Granuloma, Plasma Cell/pathology , Granuloma, Plasma Cell/physiopathology , Hip Dislocation/etiology , Hip Dislocation/physiopathology , Humans , Metals/blood , Pain/etiology , Pain/physiopathology , Peripheral Nerve Injuries/chemically induced , Peripheral Nerve Injuries/pathology , Peripheral Nervous System Diseases/pathology , Peripheral Nervous System Diseases/physiopathology , Peroneal Nerve/drug effects , Peroneal Nerve/injuries , Peroneal Nerve/pathologyABSTRACT
Atomic force microscopy (AFM) was used to measure the disjoining pressures of perfluoropolyether lubricant films (0.8-4.3 nm of Fomblin Z03) on both silicon wafers and hard drive disks coated with a diamondlike carbon overcoat. Differences in the disjoining pressure between the two systems were expected to be due to variations in the strength of van der Waals interactions. Lifshitz theory calculations suggest that this substrate switch will lead to relatively small changes in disjoining pressure as compared to the more pronounced effects reported due to changes in lubricant chemistry. We demonstrate the sensitivity of our AFM method by distinguishing between these similar systems.
ABSTRACT
The photochemical growth of silver nanoparticles on the negative domains of lead zirconate titanate thin films is reported. A sample of highly [100] orientated lead zirconate titanate, with a ratio of 30:70, that was 65-70 nm thick grown on Pt-coated MgO was poled by use of piezoresponse force microscopy to produce defined regions of surface positive and negative polarization. A comparison between the growth of silver nanoparticles on the surface of the lead zirconate titanate when illuminated with two sources of super band gap UV is given. In both cases the wavelength of illumination leads to growth on the positive domains but only illumination with a Honle H lamp, with a high photon output over 250-200 nm, caused significant growth of silver nanoparticles on the negative domain. The deposition on the negative domain is explained in terms of changed band bending due to the excitation of electrons into the conduction band, the rate of decay to the ground state, and dimensions of the ferroelectric film. The rate of deposition of silver nanoparticles on the negative domains is approximately half that on the positive domains.
ABSTRACT
We have identified conditions in which the atomic force microscope can be used to stretch a meniscus of a perfluoropolyether (PFPE) lubricant pinned between an AFM tip and a nanometer-thick PFPE film to obtain the disjoining pressure of the film. Under quasi-equilibrium conditions, the chemical potential of the film can be equated to that of the stretched meniscus. A theory is presented that provides a complete description of the capillary force of a stretched meniscus. Fits of the theory to quasi-equilibrium force-extension curves yield the effective meniscus curvature and, by extension, the disjoining pressure of the underlying film. AFM force curves collected at varying film thicknesses compare very well with predictions from Lifshitz theory of dispersive interactions in thin films, with no adjustable parameters. This complete description of meniscus deformation during atomic force microscopy force-extension experiments makes possible the measurement of unknown disjoining pressures as required for screening of lubricant-overcoat combinations required for next-generation data storage systems.
ABSTRACT
OBJECTIVE: Finding time to teach psychiatry has become increasingly difficult. Concurrently, changes in medical student education are elevating demands for teaching. Academic psychiatry is challenged by these pressures to find innovative ways to recruit, retain, and reward faculty for teaching efforts. To address this challenge, the authors recommend a multifactorial approach to meeting the medical student educational mission of psychiatry departments. METHODS: This approach includes a variety of efforts including having Chairs serve as role models, enforcing the service requirements of volunteer faculty, expanding teaching venues, providing faculty development, elevating the status of teaching through academies, attending to promotion of faculty educators, establishing and nominating faculty for teaching awards, and using medical center resources to provide rewards for teachers. CONCLUSION: Academic leaders must acknowledge the inherent value of teaching to the academic enterprise and delegate sufficient resources to recruit, retain, and reward educators for the essential work that they perform.